Originally from northeastern Pennsylvania, Johnson served in World War II before pursuing an acting career. He acted in several TV programs in the 1950s and '60s, including "The Adventures of Superman," "Alfred Hitchcock Presents" and "The Twilight Zone." However, his most famous role came along in 1964: The Professor on "Gilligan's Island."

"I've had people in the ensuing years say to 'if they did 'Gilligan's Island' today you'd all be living in the same tent,'" he told the Archive of American Television. "It's true. That innocence was kept and it worked."